There is currently great interest in methods for the preparation of selectively fluorinated organic compounds. This interest results from the profound influence that fluorine incorporation can have on the physical properties, chemical properties, and biological activity of molecules. For example, methods for putting the bulky, highly electronegative and generally inert trifluoromethyl group into organic compounds have received much research attention during recent years.
Another fluorinated substituent that could attract interest among synthetic organic chemists is the pentafluorosulfanyl (SF5) group (Winter et al., Inorganic Fluorine Chemistry—Toward the 21st Century (1994) 555:128-47, Pub: American Chemical Society: Washington (Thrasher, J. S., Strauss, S. H., Eds.); Lentz et al., Chemistry of Hypervalent Compounds (1999) 295-326; Pub: Wiley-VCH: New York (Akiba, K., Ed.); Verma et al., Advances in Inorganic Chemistry (1994) 41:125-69, Pub: Academic Press: San Diego (Sykes, A. G., Ed.); pentafluorosulfanyl groups bear some similarity to trifluoromethyl groups, however, SF5 is more electronegative (σp=+0.68 versus +0.54 for CF3; Sheppard, W. A., J. Am. Chem. Soc. (1962) 84:3072-6) and more sterically demanding.
However, until the development of the subject invention, methods for the addition of an SF5 substituent to a benzene ring or other aliphatic compounds were inconvenient, dangerous, and many methods required the use of elemental F2 or oxidative fluorination by AgF2 (Sheppard, W. A., J. Am. Chem. Soc. (1962) 84:3064-3072; Chambers et al., Chem. Commun. (1999) 883-884; Bowden et al., Tetrahedron (2000) 56:3399-3408; Sipyagin et al., J. Fluorine Chem. (2001) 112:287-295) to incorporate an SF5 group into aliphatic compounds (i.e., the methodologies relied on high pressure autoclave or specialized photochemical procedures) (Case et al., J. Chem. Soc. (1961) 2066-2070; Wessel et al., Chem. Ber. (1983) 116:2399-2407; Winter et al., J. Fluorine Chem. (1994) 66:109-116; Fokin et al., Russ. Chem. Bull. (1996) 45:2804-6). Thus, the introduction SF5 into aliphatic compounds has not been widely practiced by synthetic organic chemists.
SF5Cl is presently the only commercially available “reagent” that can be used to introduce the SF5 substituent into aliphatic compounds. As a gaseous pseudo halogen, this reagent cannot be used as an electrophilic source of SF5. It has, however, been used in free radical chain alkene/alkyne addition processes (Sidebottom et al., Trans. Faraday Soc. (1969) 65:2103-2109). These processes are generally done thermally, in an autoclave, with or without an initiator, or using room temperature gas phase or low temperature solution phase photochemical processes. For example (Case et al., J. Chem. Soc. (1961) 2066-2070): 
In order for SF5-derivatives to become incorporated into the day-to-day strategic planning of working synthetic organic chemists, a convenient bench-top procedure for the introduction of SF5 substituents into organic substrates is needed. The subject invention provides such a method—one that will allow convenient addition of SF5Cl to a large variety of aliphatic compounds (such as alkenes and alkynes) in excellent yield.